945 resultados para bis-GMA analog
Resumo:
The title compound [Ni(C20H15N2OS)(2)] is prepared by the reaction of metal acetate with the corresponding acylthiourea derivative. The complex is characterized by elemental analysis, IR, H-1 and C-13 NMR, and its structure is determined by single crystal X-ray diffraction. The Ni(II) ion is coordinated by the S and O atoms of two N-benzoyl-N',N'-diphenylthiourea ligands in a slightly distorted square-planar coordination geometry. The two O and two S atoms are mutually cis to each other. The substance crystallizes triclinic (P-1 space group) with cell dimensions a = 10.7262(9) , b = 12.938(3) , c = 14.2085(12) , alpha = 74.650(4)A degrees, beta = 78.398(4)A degrees, gamma = 68.200(5)A degrees, and two formula units in the unit cell. The structure is very close to the related N-(2-furoyl) Ni complex reported previously.
Resumo:
Schiff base ligand: N,N'-bis(1-phenylethylidene)ethane-1,2-diamine (L), was derived from acetophenone and ethylenediamine by condensation and its complexes (1-5) were prepared with Pb2+, Ni2+, Co2+, Cu2+ and Cd2+ metal ions. Their structures were characterized by FAB-MS, IR spectra, elemental analyses and molar conductance. The octahedral geometry of the complexes was proposed by electronic spectra and magnetic moment data. The conductivity data showed that the complexes have non-electrolytic nature. The complexes (1-5) have higher in vitro antimicrobial activity than the Schiff base ligand (L). In the nuclease activity, the complexes cleave DNA as compared to control DNA in the presence of H2O2.
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The ionic liquid butyltrimethylammonium bis(trifluoromethylsulfonyl)imide, [C4C1C1C1N][Tf2N], is a glass-forming liquid that exhibits partial crystallization depending on the cooling rate. Differential scanning calorimetry (DSC) indicates crystallization at T-c = 227 K, melting at T-m = 258 K, glass transition at T-g similar to 191 K, and also cold crystallization at T-cc similar to 219 K. Raman spectroscopy shows that the crystalline structure obtained by slow cooling is formed with [Tf2N](-) in cisoid conformation, whereas [Tf2N](-) in transoid conformation results from fast cooling. No preferred conformation of the butyl chain of the [C4C1C1C1N](+) cation is favored by slow or fast cooling of [C4C1C1C1N][Tf2N]. Low-frequency Raman spectroscopy shows that crystalline domains developing in the supercooled liquid result in a glacial state made of a mixture of crystallites and amorphous phase. However, these crystalline structures obtained by slow cooling or cold crystallization are not the same because anion-cation interactions promote local structures with distinct conformations of the [Tf2N](-) anion.
Resumo:
Embora os ftalatos sejam um dos poluentes mais frequentemente encontrados no meio ambiente, há escassez de dados na literatura sobre biorremediação de solos tropicais contaminados por esses compostos. Por esse motivo, este estudo avaliou a biorremediação de um solo contaminado com os plastificantes DEHP (Bis-2-etilhexilftalato), DIDP (Di-isodecilftalato) e álcool isobutílico, por uma indústria no Estado de São Paulo. A biorremediação ocorreu pela utilização de microrganismos presentes no solo e pela adição de inóculo adaptado em reator em fase de lama. O reator foi monitorado durante 120 dias, sendo corrigida apenas a umidade do solo. Os resultados indicaram que a biodegradação dos ftalatos seguiu uma cinética de primeira ordem e a biorremediação ocorreu na faixa de pH entre 7,4 e 8,4 e temperaturas entre 17 e 25 ºC, com eficiência de remoção de contaminantes acima de 70 %. Após 120 dias, o teor de DEHP estava abaixo de 4 mg kg-1, limite estipulado pela legislação brasileira para solo de uso residencial.
Resumo:
This paper reports on the advancement of magnetic ionic liquids (MILs) as stable dispersions of surface-modified gamma-Fe2O3, Fe3O4, and CoFe2O4 magnetic nanoparticles (MNPs) in a hydrophobic ionic liquid, 1-n-butyl 3-methylimidazolium bis(trifluoromethanesulfonyl)imide (BMI.NTf2). The MNPs were obtained via coprecipitation and were characterized using powder X-ray diffraction, transmission electron microscopy, Raman spectroscopy and Fourier transform near-infrared (FT-NIR) spectroscopy, and magnetic measurements. The surface-modified MNPs (SM-MNPs) were obtained via the silanization of the MNPs with the aid of 1-butyl-3[3-(trimethoxysilyl)propyl]imidazolium chloride (BMSPI.Cl). The SM-MNPs were characterized by Raman spectroscopy and Fourier trail: form infrared attenuated total reflectance (FTIR-ATR) spectroscopy and by magnetic measurements. The FTIR-ATR spectra of the SM-MNPs exhibited characteristic absorptions of the imidazolium and those of the Fe-O-Si-C moieties, confirming the presence of BMSPI.Cl on the MNP surface. Thermogravimetric analysis (TGA) showed that the SM-MNPs were modified by at least one BMSPI.Cl monolayer. The MILs were characterized using Raman spectroscopy, differential scanning calorimetry (DSC), and magnetic measurements. The Raman and DSC results indicated an interaction between the SM-MNPs and the IL. This interaction promotes the formation of a supramolecular structure close to the MNP surface that mimics the IL structure and is responsible for the stability of the MIL. Magnetic measurements of the MILs indicated no hysteresis. Superparamagnetic behavior and a saturation magnetization of similar to 22 emu/g could be inferred from the magnetic measurements of a sample containing 50% w/w gamma-Fe2O3 SM-MNP/BMI-NTf2.
Resumo:
This work presents the analog performance of n-type triple-gate MuGFETs with high-k dielectrics and TiN gate material fabricated in 45 degrees rotated SOI substrates comparing their performance with standard MuGFETs fabricated without substrate rotation. Different fin widths are studied for temperatures ranging from 250 K up to 400 K. The results of transconductance, output conductance, transconductance over drain current ratio, intrinsic voltage gain and unit-gain frequency are studied. It is observed that the substrate rotation improves the carrier mobility of narrow MuGFETs at any temperature because of the changing in the conduction plane at the sidewalls from (1 1 0) to (1 0 0). For lower temperatures, the improvement of the carrier mobility of rotated MuGFETs is more noticeable as well as the rate of mobility improvement with the temperature decrease is larger. The output conductance is weakly affected by the substrate rotation. Although this improvement in the transconductance of rotated MuGFETs is negligibly transferred to the intrinsic voltage gain, the unity-gain frequency of rotated device is improved due to the larger carrier mobility in the entire range of temperatures studied. (C) 2011 Elsevier Ltd. All rights reserved.
Resumo:
This paper presents a technique for performing analog design synthesis at circuit level providing feedback to the designer through the exploration of the Pareto frontier. A modified simulated annealing which is able to perform crossover with past anchor points when a local minimum is found which is used as the optimization algorithm on the initial synthesis procedure. After all specifications are met, the algorithm searches for the extreme points of the Pareto frontier in order to obtain a non-exhaustive exploration of the Pareto front. Finally, multi-objective particle swarm optimization is used to spread the results and to find a more accurate frontier. Piecewise linear functions are used as single-objective cost functions to produce a smooth and equal convergence of all measurements to the desired specifications during the composition of the aggregate objective function. To verify the presented technique two circuits were designed, which are: a Miller amplifier with 96 dB Voltage gain, 15.48 MHz unity gain frequency, slew rate of 19.2 V/mu s with a current supply of 385.15 mu A, and a complementary folded cascode with 104.25 dB Voltage gain, 18.15 MHz of unity gain frequency and a slew rate of 13.370 MV/mu s. These circuits were synthesized using a 0.35 mu m technology. The results show that the method provides a fast approach for good solutions using the modified SA and further good Pareto front exploration through its connection to the particle swarm optimization algorithm.
Resumo:
A tank experiment was conducted to check if self-potential (SP) signals can be generated when buried organic matter is wire-connected to a near-surface, oxygen-rich, sediment layer. This experiment demonstrated that once wired, there was a flux of electrons (hence an electric current) between the lower and upper layers of the sandbox with the system responding as a large-scale microbial fuel cell (a type of bioelectrochemical system). An electric current was generated by this process in the wire and the SP method was used to monitor the associated electric potential distribution at the top of the tank.. The electric field was controlled by the flux of electrons through the wire, the oxidation of the organic matter, the reduction of oxygen used as a terminal electron acceptor, and the distribution of the DC resistivity in the tank. The current density through the wire was limited by the availability of oxygen and not by the oxidation of the organic matter. This laboratory experiment incorporated key elements of the biogeobattery observed in some organic-rich contaminant plumes. This analogy includes the generation of SP signals associated with a flux of electrons, the capacity of buried organic matter in sustaining anodic reactions, network resistance connecting terminal redox reactions spatially separated in space, and the existence of anodic secondary coupled reactions. A resistivity tomogram of the tank, after almost a year in operation, suggests that oxidative processes triggered by this geobattery can be imaged with this method to determine the radius of influence of the bioelectrochemical system.
Resumo:
Embora os ftalatos sejam um dos poluentes mais frequentemente encontrados no meio ambiente, há escassez de dados na literatura sobre biorremediação de solos tropicais contaminados por esses compostos. Por esse motivo, este estudo avaliou a biorremediação de um solo contaminado com os plastificantes DEHP (Bis-2-etilhexilftalato), DIDP (Di-isodecilftalato) e álcool isobutílico, por uma indústria no Estado de São Paulo. A biorremediação ocorreu pela utilização de microrganismos presentes no solo e pela adição de inóculo adaptado em reator em fase de lama. O reator foi monitorado durante 120 dias, sendo corrigida apenas a umidade do solo. Os resultados indicaram que a biodegradação dos ftalatos seguiu uma cinética de primeira ordem e a biorremediação ocorreu na faixa de pH entre 7,4 e 8,4 e temperaturas entre 17 e 25 ºC, com eficiência de remoção de contaminantes acima de 70 %. Após 120 dias, o teor de DEHP estava abaixo de 4 mg kg-1, limite estipulado pela legislação brasileira para solo de uso residencial.
cis-Bis(1,10-phenanthroline-j2N,N0)bis-(pyridin-4-amine-jN1)ruthenium(II) bis(hexafluoridophosphate)
Resumo:
In the title complex, [Ru(C12H8N2)2(C5H6N2)2](PF6)2, the RuII atom is bonded to two -diimine ligands, viz. 1,10- phenanthroline (phen), in a cis configuration, in addition with with two 4-aminopyridine (4Apy) ligands, resulting in a distorted octahedral coordination geometry. N—H F hydrogen-bonding interactions play an important role in the crystal assembly: 21-screw-axis-related complex molecules and PF6 counter-ions alternate in helical chains formed along the a axis by means of these contacts. N—H contacts (H centroid = 3.45 A ° ) are responsible for cross-linking between the helical chains along [001].
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The aim of the present study was to evaluate the LH surge after EB (estradiol benzoate) or GnRH administration with or without P4 (progesterone) pre-exposure in ovariectomized (OVX) buffalo cows. Females were randomly assigned to receive an intravaginal P4 device (D0–D9). They were then given EB 24 h or GnRH 36 h post-P4 device removal (factorial 2×2, n=6 per group). Blood collection for LH measurement began 36 h after the P4 device removal and continued at 3 h intervals. The area under the LH curve (AUC; 30.2 ng2 and 13.41 ng2; P=0.007) and the area of the LH peak (AP; 19.0 ng2 and 8.9 ng2; P=0.009) were greater for EB than GnRH. We did not observe an effect of P4 pre-exposure on the AUC and AP. Furthermore, there was no interaction between P4 pre-exposure and EB or GnRH treatment on the AUC and AP. However, there was an interaction (P<0.01) between P4 pre-exposure and the type of inducer (EB or GnRH) to release a preovulatory-like LH surge at the beginning (BP), final (FP) and time (TP) of the LH peak. The P4 pre-exposure anticipated the BP (2.5 and 7.4 h), TP (6.0 and 12.0 h) and FP (11.5 and 17.1 h) when EB was used to induce a preovulatory-like LH surge (P<0.01). However, there was no effect of P4 pre-exposure on BP (0.4 and 0.4 h), TP (3.0 and 3.0 h) and FP (5.9 and 6.1 h) with GnRH treatment. There was also no effect of the pre-exposure to P4, type of inducer or interaction on the amplitude of the LH peak. We concluded that EB therefore led to greater LH release than GnRH, and pre-exposure to P4 before EB administration anticipated the preovulatory-like LH surge in buffalo cows.
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Synthese und Charakterisierung neuer funktionalisierter Mono- und Bis-tetrahydro-pyrrolo[3,4-b]carbazole als potentielle DNA-Liganden In der Carbazol-Chemie sollen neue anellierte Verbindungen mit potentieller DNA-Affinität und damit verbundener Antitumoraktivität entwickelt werden. Auf molekularer Ebene sind DNA-Interkalation oder DNA-Rinnenbindung zu erwarten. Darauf aufbauend wurden in Anlehnung an literaturbekannte Cytostatika Mono- und Bis-tetrahydropyrrolo[3,4-b]carbazole synthetisiert, die zur Entwicklung neuer Leitstrukturen bzw. -substanzen beitragen können.In der vorliegenden Arbeit wurde als synthetische Schlüsselreaktion die in unserem Arbeitkreis etablierte Indol-2,3-chinodimethan-Diels-Alder-Reaktion mit geeigneten cyclischen Mono- und Bismaleinimiden als Dienophilen weiterführend genutzt. Auf Grund des Aufbaus von künftigen Struktur-Wirkungsbeziehungen wurden variable Linker zwischen die beiden zu verbindenden Pyrrolotetrahydrocarbazole eingeführt. Diese waren aliphatischer und diamidischer Natur. Diamidische Strukturelemente wurden im Hinblick auf die Entwicklung neuer Peptidomimetika eingeführt. Deren Synthese gelang zum einen über die gemischte Säureanhydrid-Methode und zum anderen über die Azolid-Methode. Die Struktursicherung der als Cycloaddukte erhaltenen Tetrahydrocarbazole erfolgte mittels Standardverfahren (1D-, 2D-NMR-, IR-Spektroskopie und Massenspektrometrie).Enantiomere bzw. Diastereomere chiraler Wirkstoffe unterscheiden sich stark in ihren pharmakologischen Eigenschaften, deshalb müssen Verfahren entwickelt werden, um diese Substanzen gegebenenfalls auch in enantiomerenreiner Form darstellen zu können. Die Racemate der Monotetrahydrocarbazole und die Racemate sowie die dazu diastereomeren meso-Formen der Bistetrahydrocarbazole, die bei der Reaktion entstehen, konnten erstmals mittels chiraler HPLC analytisch getrennt werden.In einer der Synthese ergänzten theoretischen Studie wurde Computer-Molecular-Modelling zur Problematik der Diels-Alder-Reaktion durchgeführt, außerdem wurden kraftfeld-mechanische Berechnungen zur Konformationsanalyse der 'einfachen' Monotetrahydro-carbazole herangezogen und darauf aufbauend schließlich einfache DNA-Docking-Experimente zur ersten Abschätzung des DNA-Binde-Verhaltens der synthetisierten Verbindungen vorgenommen.
Resumo:
Abstract deutsch Die im Rahmen dieser Arbeit dargestellten Anthracen-amphi-chinone wurden durch Oxidation ihrer 9,10-Dihydro-2,3,6,7-tetrahydroxy-Derivate gewonnen, während zwei literaturbekannte Anthracen-amphi-chinone aus den entsprechenden 2,3,6,7-Tetrahydroxy-anthracenen dargestellt wurden. Bei gleicher Substitution wurden identische Produkte gefunden.Die entstandenen Produkte sollten in Diels-Alder-Reaktionen umgesetzt werden. Von allen Hydroxyverbindungen konnten bei der Oxidation mit 2,3-Dichlor-5,6-dicyano-p-benzochinon in Gegenwart von Cyclooctin die entsprechenden Cyclooctin-Addukte erhalten werden. Dadurch wurde nachgewiesen, daß die Oxidationen über die Bis-o-chinone verlaufen, obwohl es nicht gelang, Bis-ortho-benzochinone zu isolieren, die in 9- und 10-Stellung ein Protonen tragen. Stattdessen erhielt man durch eine Keto-Enol-Tautomerie die entsprechenden amphi-Chinone.Drei Bis-chinone wurden direkt mit Cyclooctin umgesetzt und lieferten bei gleicher Substitution die identischen Reaktionsprodukte. Die Cyclooctin-Addukte reagierten beim Bestrahlen durch CO-Eliminierung zu Kohlenwasserstoffen.Bei der Oxidation der Hydroxyverbindungen mit DDQ in Gegenwart von Pentamethyl-cyclopentadien erhielt man die entsprechenden PMCP-Addukte. Dabei reagieren die Chinone als Heterodien.Die Reaktivität von 1,5-Cyclooctadiin mit ortho-Benzochinonen wurde durch die Umsetzung mit 4,5-Dimethyl-ortho-benzochinon untersucht. Dabei wurde festgestellt, daß das Diin mit zwei Molekülen des Chinons reagiert.Mit den erhaltenen Ergebnissen wurde eine Diels-Alder-Polyaddition von 9,10-Dihydro-9,10-ethano-9,10-dimathyl-anthradichinon-(2,3;6,7) mit 1,5-Cyclooctadiin durchgeführt. Bei dieser Reaktion gelangte man zu Oligomeren.